Domino Effect
by beibet1008
Summary: It's been 5 months since the end of the Dark War, and everything is finally perfect. That is, until Clary finds Jace in bed with Aline. She can't take it. So she runs away, with the promise of coming back. Will she be able to forgive and forget, or is this the end? What will happen when she comes back a year later and are new dangers awakening?
1. Chapter 1

Things had been going so great since the end of the Dark War. Everything seemed to fall into place. Jocelyn and Luke had gone on their honeymoon that night, and would be gone for at least the next three months. Simon had started his shadowhunter training, and his memory was coming back little by little. Jordan's death had meant that Simon was alone in his apartment, so Isabelle had convinced him to move into the institute, where Clary was staying until her parents got back. Alec had moved back into Magnus's apartment, and Robert and Maryse spent almost all of their time in Idris, trying to help the Clave repair the damages Jonathan's endarkened had caused on the beautiful city.

And Jace? Her relationship with Jace was moving steadily forward. They spent most of their time together, including their nights. He continued training her and teaching her everything he possibly could about the shadow world. They were inseparable. Which was exactly why it felt as if she had been stabbed with a seraph blade when she found him in bed with Aline.

 _Flashback:_

 _She had told him she would be at an art class, but she had really traveled to Alicante, to pick up the present she had bought for him. Not that it was his birthday or anything, but she had seen it in passing, and just had to get it for him. She had even had it engraved._

 _She couldn't wait to see the look on his face when he saw it. She had drawn a portal as fast as she could, and walked quietly, intending to surprise him._

 _Unfortunately, she had been the one to gasp in surprise when she opened the door to see Jace and Aline on the bed, naked, in the full stages of sex. Even more unfortunately, they were completely uncovered, so she saw everything. EVERYTHING. Not only was she heartbroken, but she was scarred for life._

 _Jace had looked over at the sound of her gasp, and sprung up, tossing Aline aside like a rag doll. "Clary! I- we-."_

 _She turned. And ran. LIKE HELL. Unfortunately, that doesn't mean much when your boyfriend is faster than Sonic-X. He had caught up to her before she could reach the elevator, calling her name. She bolted for the stairs, grabbing her stele and drawing a speed rune on her wrist, not a second too late. His fingers brushed her forearm, before she sped up. When she got to the bottom, she slammed the door shut, gaining her a minute or so, as he was thrown off for a moment._

 _She ran through the sanctuary as fast as she could, trying to ignore the steady flow of tears that streamed down her face. However, before she could make it through the doors, they opened, and the entire gang flooded in. Isabelle, Simon, Magnus, and Alec all paused as she skidded to a halt, looking for another exit._

 _Isabelle sucked in a breath. "Clary?! What-"_

" _Clary, wait!"_

 _She whirled as Jace stopped in front of her. His hair was tousled, his lips were swollen, and he had at least two hickeys on the right side of neck. He was half-naked, his black boxers being the only thing keeping him decent._

 _She let out a sob, stepping back and putting her hands to ward him off. "Don't- please just-"._

 _He cut her off, his eyes watering as he grabbed her hands. "Clary, please! Just-"._

" _DON'T TOUCH ME!" She yanked her hands out of his, pacing back and forth, her hands pushing her hair out of her face, before looking up at him, betrayal shining most brightly in her eyes. "How could you?! After EVERYTHING we've been through, how could you do this to me?!"_

" _Clary, please just hear me out! I can explain! I- Aline and I-"._

 _She held up a hand, cutting him off again. "I can't listen to you talk right now. I just need a moment to get myself together."_

 _She started pacing again, her hands running through her hair, as she tried to keep her level of hysteria down. She wiped her tears on her exposed wrist, glancing back at the others who were watching with mixed expressions, before shaking her head. "I, uh… I think I need a break for a while."_

 _A tear rolled down his left cheek. "Clary… please just hear me out."_

 _She shook her head. "I don't want to hear anything right now. I just need to know… do you still love me?"_

 _He took a step towards her, a silent sob escaping him, as he cupped her cheeks. "Of course I do. I'll never love anybody other than you. You're my entire life, Clary. My everything. I'm nothing without you... I love you so much, it kills me."_

 _The tears streamed, as she put a hand over one of his. His thumbs brushed away her tears, as she looked up at him, blurry-eyed. He bent down, brushing his lips against hers, resting his forehead against hers._

 _She stayed like that for a while, before stepping back. "I'll come back. If you really do love me, then I'm sure we can work this out." She took the hand that was still pressed to her hand, and put the sheathed sword in it. "This is my promise to you."_

 _She looked up at him one last time, before turning, smiling quickly at the others. "I'll keep in touch. I promise."_

 _And she ran._


	2. Chapter 2

So, where was she now, two days after running away from her supposedly perfect relationship?

 _Prague._ Of course she would end up in Prague. When she had drawn the portal from Luke's apartment, it had been a spur of the moment kind-of thing. Not to mention she had been panicking and bawling her eyes out at the same time.

 _Flashback (again):_

 _Luke's was the first place she had run to, throwing the door open to her room, and throwing every item of clothing into the biggest bag she could find._

 _She glanced in the mirror as she passed it. Her eyes were read and puffy, still streaming with tears. Her hair was frizzy and messy from running her hands through it. She looked… awful. No, not awful. Heartbroken. Which she WAS! This didn't feel at all like she had read it. It felt like her heart had been ripped out of her chest, stomped on, microwaved and deep-fried, then shoved back in, leaving a gaping hole. In simpler words, it SUCKED!_

 _She froze, mid-step when she heard the front door slam open, and Jace screaming her name. She heard him running around the house trying to find her, and she sprung back into action, shoving her gear and seraph blades in her suitcase and zipping it hastily, before drawing a locking rune on her closed door._

 _Not a second later, Jace was banging on it. "Clary! Open the door. Clary, open the door. I just want to talk! Please, just open the door."_

 _She walked towards the door. "Jace, I promised I'd come back. Why did you come here?"_

" _I'm so, so sorry Clary. It was a mistake. It was a huge mistake. I don't know what I was doing, I ju-"._

" _Please stop. I can't listen to this right now. Just leave me alone." She was trying as hard as she possibly to could not to cry, so it came out sounding strangled._

 _He stopped banging. "Where are you going?"_

 _She hesitated. "I don't know. But I can't stay here. Not right now."_

" _How long will you be gone?"_

" _I don't know. Until I can come back without feeling the urge to murder you."_

 _She could practically see him smiling softly through the door. "You just have to know… I will never love anybody as much as I love you. And I'm prepared to wait forever for you."_

 _She turned, the tears streaming faster than ever, and made the portal, jumping through before she could change her mind._

 _End of flashback_

And of course the portal would take her to Prague. The only place out of the United States that she and Jace had been to together, not including Idris and Edom. And to make matters worse, she recognized her surroundings.

The small bridge she was now standing on was all too familiar, and brought back painful memories. True, he had been under Jonathan's control then, but he had still loved her. He'd loved her so much, he still felt it when he was being possessed. Literally.

She walked away quickly before she could start crying again, unconsciously making her way to the only place she knew. When she got there, it was exactly as it had been when they had left. She could remember the exact feel of Jonathan's crossbow digging into her back after she had destroyed the familiar apartment, on their way to The Seventh Sacred Site.

She shook her head, trying to clear the bad memory away, and examined the apartment. It wasn't that bad. Nothing one of her special repair runes couldn't handle.

She set to work quickly, drawing a repair on the front door and the side of the apartment, before stepping back and watching the mini-house repair itself. The ceiling came together and the broken glass fit together like puzzle pieces to rebuild the windows. She waited until it was completely fixed before drawing a concealment rune on the front door to keep the mundanes from seeing it.

 _This isn't permanent. Just until I can get myself together. Until I can see Jace again without crying,_ she thought.

 _But then again, this could be my chance at a new life, if I decided to stay here,_ a voice said to her mind.

 _Jace will come looking, eventually and then what will I do?_

 _Run. There's nothing wrong with running from someone who broke your heart. You're looking out for yourself. That's what shadowhunters do._

 _No, they don't. They look out for each other. I will go back eventually and work this out._

Jace Pov.

 _She's gone. She's really gone. What have I done? What do I do?_

That was the only thing he could think as he ran back to the institute as fast as he could. It was like a theme song to a horror film. It froze his blood and sent shivers down his back.

He burst through the sanctuary doors, running straight to the dining room, where he knew everybody would be.

Isabelle and Simon stood on one end of the table, and Magnus and Alec on the other. Simon had his arm around Isabelle's waist,holding her back from jumping across the table at her older brother. Alec was shouting just as loud, waving his arms to prove his point.

"Damn it, Isabelle! All I'm trying to say is that maybe he had a reason for cheating on her! We have to at least try to listen to what he has to say! He might have a reasonable explanation!"

"A reason?! Are you kidding me? What logical reason would he have for cheating on Clary? _Oh, I was horny and I didn't want to inconvenience you, so I called someone._ Is that you're version of a REASONABLE EXPLANATION?"

Magnus butted in. "Would you two shut up already?! Since Jace is already here, why don't we ask him?"

They all immediately turned to him, and Isabelle stomped towards him, before Simon caught her by the waist again.

"Let me go, Simon! I swear on the Angel, I'm gonna kill him and you if you don't let me go."

Jace yanked a stele off the table, and ran to his room, grabbing the picture of him and Clary off the nightstand, and drawing a tracking rune, waiting anxiously. His heart dropped when nothing happened, and he ran back downstairs, looking at Magnus. "A tracking spell. I need a tracking spell."

He was about to respond, when Maryse and Robert walked in, looking around with solemn expressions.

Alec started. "Mom?! What are you doing here?!"

"Where's Clary?"

They all froze. "Why?"

She sighed. "It's about Luke and Jocelyn. Something's happened."


	3. Chapter 3

Jace Pov:

"What do you mean? What's wrong?"

Maryse clasped her hands together tightly. "I mean the Clave got a fire message from Jocelyn saying they were under attack and needed help. By the time they got there, the beach house they were staying at was in flames, and they were nowhere to be found. Search parties are scouring the island as we speak, but they haven't found anything yet. I immediately came here to check on and inform Clary. Where is she?"

He froze. "Umm… about that…"

Clary Pov:

She had just finished refurbishing everything to her liking, before plopping down on the leather couch. It didn't look like when the three of them had been there, and that was good. There were too many memories in that apartment, good and bad. _This_ apartment was perfect. just like she'd always imagined her first apartment. There was a living and dining area close to the kitchen, and upstairs there were two bedrooms, one being a master and the other a guest. She had the master look almost identical to her bedroom at her original apartment with Jocelyn and Madame Dorothea.

Speaking of Jocelyn, she'd probably have to call her soon. No doubt one of them had taken the liberty of calling and telling her mother, who was probably going frantic looking for her right now.

She sighed. "I'll call her tomorrow. It hasn't been that long, I'm sure they don't even know I'm gone yet . If I tell them now I'll just worry them even more. I'll call her first thing in the morning,but I should call someone…".

She browsed through her short contact list looking for someone she could trust that wouldn't freak out. Simon. He had always been her go-to when she needed to confide in someone, and nothing had changed.

She took a deep breath before pressing the call button. This wasn't going to be easy.

Jace Pov:

He had just finished explaining the situation to Maryse, who was looking at her adoptive son in a mixture of disappointment and anger. It was silent as everyone stared at him and each had just his way through the living room wall that attached to their kitchen. He had been on a roll, and not even Alec and Isabelle together were able to stop him. It wasn't until Simon and Magnus had stepped in that he had finally been contained. Now, all he wanted to do was go to his room and wallow in his self-hate and pity. He stared down at his torn and bloody knuckles, amazed how even the blood that streamed down his arm reminded him of Clary's long red hair.

A shrill cry rang through the air, startling everyone. Simon laughed nervously, reaching into his pocket. "Sorry." He pulled it out and checked the caller i.d, his eyes widening as he answered it. "Clary?"

Everyone immediately perked up, and Jace flew to his feet. "Is she alright? Where is she?"

Simon glared at him, turning his attention to Maryse who was walking towards him, her hand outstretched. He handed it to her without another word, as Clary continued to talk through the phone. "Clary? It's Maryse. Listen, something happened and I need you to come over quickly... No, I'll tell you everything when you get here… okay, bye."

She handed Simon back his phone, sighing. "She'll be here in ten minutes."

Jace slumped slightly, not sure how he should react. Maryse walked out and Alec rested a hand on his parabatai's shoulder. "I'd figure out what I was going to say to her when she gets here if I were you. Knowing her, she won't give you much time, if any at all."

He glared at the black-haired boy. "Thanks for those words of wisdom, Alec. You're really helpful."

Alec rolled his eyes. "Don't get mad at me. You got yourself into this mess."

He didn't reply. He knew this was his fault, but he wasn't sure if he was gonna get out of this one. He had dug too big a whole, and now he was being buried alive by his own stupidity and guilt.

What was he going to do? Say that he didn't mean it? He couldn't very well lie to her. He's never lied. And he wasn't going to start now. Not when his entire life was on the line.

It wasn't for another fifteen minutes that they felt the ground shake by the opening of the portal. Jace had to restrain himself from running to her, reminding himself that he'd broken her heart only hour and half ago. He couldn't go running towards her. She'd probably break his nose if he got too close.

He waited impatiently, his knees bouncing up and down. He jumped slightly when the door was thrown open and Clary walked through, wearing a pair of tight gray trackies and a graphic tee with converse. Her long red hair was up in a messy bun, strands escaping and curling against her neck and face. Her cheeks were slightly flushed, and her eyes were rimmed with red.

Isabelle pounced on her first, hugging the small girl to her chest, suffocating her. "Oh my Angel, Clary! Do you have any idea have worried we've been! You can't just leave like that!"

Clary tried to say something, but her face was smushed into the tall girl's exposed cleavage, restricting her from talking or breathing. She groaned, her arms attempting to pry the black-haired beauty off her.

Simon laughed. "Uhh… Izzy? I don't think she can breathe…"

Iz looked down at her. "Oh, right." She let go of the smaller girl, stepping back a little. Clary gasped for breath, bracing her hands on her knes for support.

"Those things could be used as weapons."

Izzy hit her as the others laughed. Clary winced, rubbing her now sore arm. Simon hugged her next, wrapping his arms around her. Jace twitched in jealousy, his hands forming into fists. They let go after a minute, and Clary looked around, her eyes landing on him for a moment, before quickly looking away. She turned to Maryse, her hands on her hips. "So what's up? What happened?"

Maryse sighed. "You may want to sit down."

Clary's eyes widened. "What? Why?"

She sighed again. "Your parents. The island they were staying on was attacked."

Her hands fell from her hips. "What?! Where are they? Are they okay? Why didn't the Clave contact me?"

Maryse stood up. "We don't know any details yet. A fire message was sent to the Clave saying that their island was under attack and that they needed help. When they got there, the cottage was on fire, and there was no trace of them. They're still searching for them."

Clary's eyes were wide, and she stood there in shock for a moment, before turning towards the door. Izzy grabbed her arm. "Where are you going?"

"To go help look for them, of course. What else would I be doing?"

Robert finally stood up. "You can't. It's a private investigation."

Clary laughed, her eyes incredulous. "Private? Those are my parents! I'm GOING to help look for them."

She tried to walk away again, but Izzy tightened her grip on her arm. "Clary they won't let you. They'll just send you right back."

She snorted. "Like give a shit. That's my family. Nobody can stop me from doing this. Let go, Iz."

Simon sighed, running a hand through his curly hair. "Clary, maybe you should just let them handle this. You-".

"They're the only family I have left, Simon!". She turned towards them, her eyes blazing. "I've already killed all of my other family! There's no way in hell I'm gonna let them die now! They're all I have left!".

She yanked her arm from Izzy's and walked out, leaving them all in shock.


	4. Chapter 4

Clary POV:

When she got to the island, she was immediately surrounded by armed shadowhunters. After taking one look at her, however, they backed off. She pushed through the crowd and ran down the beach, where she knew the cottage was. Or at least where it had been. All that was left now was a large pile of ash, burnt appliances, and an untouched, stainless steel refrigerator. She ran a hand through her hair, before wandering throughout the house, looking for anything that might help explain exactly what happened, When she found nothing, she wandered back to where she had started and plopped down in the ash, scratching her head wildly in frustration, before taking a few deep breaths.

 _Focus Clary. They have to have left something that would tell you what happened. Even if it were a surprise attack, they would have left something behind to give you a clue. Something only you would realize was off… Something the Clave wouldn't think about… Something mundane…_

She looked up, glancing around, when her eyes caught on the burnt stove. It was pitch black, covered in soot and ash, but Clary moved towards it instinctively.

 _Flashback:_

" _Now listen, Clary. If mommy doesn't come home sometime or if mommy's in trouble I want you to go straight to Uncle Luke. He'll make sure you're safe."_

 _A six-year-old Clary cocked her head. "But what if Uncle Luke is in trouble too?"_

 _Jocelyn paused, before thinking about it for a moment. "Ok, if you go to Uncle Luke's and he's not there either, than I want you to come straight back here and look in our special hiding spot."_

 _Her mother pulled her into the kitchen, before looking around. Her eyes stopped on the oven, before leaning down to her daughter's height and putting her hands on her shoulders. "Listen, sweetheart. If anything ever happens to Uncle Luke and I at the same time, I want you to look in our special hiding place. Do you know where our special hiding place is?"_

 _Little Clary shook her head. Her mother smiled at her. "The oven honey. If anything ever happens and you're left on your own I want you to check the oven. Everywhere. Under, in, behind, in the burners, everywhere, ok? And you can't tell anyone about this, not even Simon or Luke. This is our little secret, ok?_

 _Clary nodded, and her mother hugged her as she looked over her shoulder at the oven, wondering if she would ever have to use that hiding spot, and why._

Clary moved closer to the oven and began searching. After searching on top of, on the sides, and underneath, she opened the door and began looking.

A small piece of paper was taped to the top and she immediately pulled it off and stuffed it into her pocket, before anyone could see. She walked around the small cottage once more, before heading outside, surprised to see the Lightwoods, Magnus, and Simon being held back by Clave Members. She glanced at them quickly to see that everyone on the beach was staring at her, before realising that they were actually staring past her. She turned slowly, and froze.

No. No, no, no, no, no, no, no, no, no, no! She walked slowly towards the small sitting area to the side of the house, her heart pounding in her ears. There under a giant pile of burnt trees, a hand looked almost as if it were reaching out towards her.

"No, no, no, no, no no!", she shouted as she ran towards the pile. She lifted the trees off without thinking, and threw them off with a heave, not caring when her hands dripped with blood from the sharp edges and splinters.

She froze, and her heart felt as if it frozen in her chest. Her mother lay over Luke. They were both covered in ash, but that did nothing to hide the stab wounds that littered her parents bodies. The ash mixed with blood to make something that looked like tar that covered their entire bodies. Their eyes were closed, and their faces unflinching.

Clary collapsed to her knees, pulling her mom up to press her chest against her cheek. Nothing. Not a damn thing. "Mom. Mom! MOM. MOM!"

She slapped her mother's cheeks as if that were gonna make a difference, before checking Luke for a pulse. Nothing.

"No! NO! NO! NO! NO! NO! NO! NO! You can't leave me! NO, NO NO! Don't leave me! MOM! LUKE!" She clutched onto her parents bodies as she screamed and cried.

Distantly, she heard people behind her, and felt several pair of hands touch her, but she was too busy wailing to notice. Her forehead against Luke's and her arms around her mother, she screamed louder than she's ever screamed in her life.

Than hands came around her waist, lifting her to her feet. She fought back quickly, and heard a cry of pain as she broke a nose with her elbow. More hands came and pulled her off her parents, even as she fought harder and harder the further she go from her parents, tears blurring her vision to the point that it was almost impossible to see anything. She managed to injure two others as she became frantic, before a tingling sensation overcame her, and she collapsed again. She froze there for a second, her vision turning black, before falling on her side, with the image of her dead parents searing the inside of her eyelids as they closed.


End file.
